Aortic valve stenosis is the most common debilitating valvular heart lesion in old patients. Transcatheter aortic valve replacement (TAVR) is an emergent technique for high-risk patients with aortic stenosis. In recent times, treatment has expanded to also include low- and intermediate-risk individuals. General anesthesia offers many advantages, mainly regarding the possibility of an early diagnosis and treatment of possible complications through the use of transesophageal echocardiography. Propofol is the most used sedative-hypnotic agent for the induction and maintenance of general anesthesia. However, adverse events such as hypotension, and bradycardia are associated with propofol sedation. Ciprofol is a novel anesthetic/sedative agent similar to propofol, with an equivalent efficacy ratio to propofol of 1/4 to 1/5. Ciprofol has properties of fast onset of action, rapid recovery, reduced injection pain and stable cardiorespiratory function, making it a promising alternative to propofol. The aim of this study is to explore the safety and efficacy of ciprofol when used for general anesthesia in patients undergoing transcatheter aortic valve replacement compared to propofol.

After assessing patient eligibility, they were randomly assigned to two equally sized groups.Patients in this study were fasted for a minimum of 8 h without premedication.

Following arrival in the operating room, patients were monitored with electrocardiography, respiratory rate, pulse oximetry, bispectral index (BIS), cerebral oxygen saturation,and continuous invasive arterial blood pressure. Induction of anesthesia： group ciprofol received an IV injection of ciprofol at a dose of 0.2-0.4 mg/kg, and administration time of 30 s； group propofol received an IV injection of propofol at a dose of 1.0-2.0 mg/kg, and administration time of 30 s.

When the eyelash reflex disappeared and the BIS value was ≤60 administration was stopped, followed by an IV injection of alfentanil 30 μg/kg and rocuronium 0.6 mg/kg.

Endotracheal intubation was performed when alfentanil and rocuronium had fully worked, and the BIS value was <50. A ventilator was then connected for mechanical ventilation using the following parameters: VT 6-8 ml/kg, RR 12-20 times/min, the inspiratory-to-expiratory ratio of 1:2, oxygen flowed 2 L/min, and maintaining PETCO2 at 35-45 mmHg (1 mmHg=0.133 kPa).

Maintenance of anesthesia:

group ciprofol received an IV infusion of ciprofol 0.8-2.4 mg·kg-1·h-1； group propofol received an IV infusion of propofol 4-6 mg·kg-1·h-1 .

Inclusion Criteria:

• patients planned for transfemoral transcatheter aortic valve replacement
• expected duration of surgery ≥ 1 and ≤ 3h
• patients undergoing general anesthesia
• no gender limit，age≥60 years，≤85 years
• BMI ≥18 and ≤30kg/m2
• ASA physical status 3~4
• be able to understand the procedures and methods of the trial and voluntarily sign the informed consent form

Exclusion Criteria:

• predicted presence of difficult airway or previous history of difficult airway
• allergic to eggs, soy products, propofol, and opioids and their antidotes
• patients with shock or hypotension that is difficult to correct with vasopressor
• patients with mental, nervous system diseases, long-term use of sedatives or antidepressants
• HB < 10.0 g/dL (100 g/L)
• patients with previous long-term use of sedative and analgesic drugs
• patients with severe heart，lung，liver and kidney disease
• not suitable for participation in this study as assessed by the investigator